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Convert Semitones to Frequency

ucnv_semitone_to_hz.Rd

Converts semitone values to frequency in Hz relative to a reference frequency. This is the inverse of ucnv_hz_to_semitone.

Usage

ucnv_semitone_to_hz(
  semitone,
  ref_freq = NULL,
  ref_source = c("A4", "UEP83", "Praat"),
  as_units = NULL
)

Arguments

semitone

Numeric vector or units object with semitone values.

ref_freq

Reference frequency in Hz. Default is NULL, which uses the reference determined by ref_source. Can also be a units object. If specified, overrides ref_source.

ref_source

Character string specifying the reference standard. Options are:

  • "UEP83": UEP 1983 standard (110 Hz = A2)

  • "Praat": Praat convention (100 Hz)

  • "A4" (default): Concert pitch A4 = 440 Hz

Ignored if ref_freq is explicitly specified.

as_units

Logical. If TRUE, returns a units object with "Hz" units.

Value

If as_units = TRUE: a units object with "Hz" units. Otherwise, a numeric vector of frequencies in Hz.

Details

The conversion formula is: $$f = f_{ref} \cdot 2^{ST/12}$$

See ucnv_hz_to_semitone for details on reference standards.

See also

ucnv_hz_to_semitone

Examples

if (FALSE) { # \dontrun{
# Using different reference standards
ucnv_semitone_to_hz(12, ref_source = "UEP83")   # 220 Hz (octave above 110)
ucnv_semitone_to_hz(12, ref_source = "Praat")   # 200 Hz (octave above 100)
ucnv_semitone_to_hz(12, ref_source = "A4")      # 880 Hz (octave above 440)

# Musical scale from A4
ucnv_semitone_to_hz(0:12, ref_freq = 440)
} # }